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advcap.c revision 1.16 
      1 /*	$NetBSD: advcap.c,v 1.16 2015/11/11 07:48:41 ozaki-r Exp $	*/
      2 /*	$KAME: advcap.c,v 1.11 2003/05/19 09:46:50 keiichi Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 1983 The Regents of the University of California.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the University nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * remcap - routines for dealing with the remote host data base
     35  *
     36  * derived from termcap
     37  */
     38 #include <sys/types.h>
     39 #include <sys/uio.h>
     40 #include <unistd.h>
     41 #include <fcntl.h>
     42 #include <ctype.h>
     43 #include <stdlib.h>
     44 #include <stdio.h>
     45 #include <syslog.h>
     46 #include <errno.h>
     47 #include <string.h>
     48 #include "pathnames.h"
     49 #include "prog_ops.h"
     50 
     51 #ifndef __UNCONST
     52 #define __UNCONST(a)		((void *)(unsigned long)(const void *)(a))
     53 #endif
     54 
     55 #ifndef BUFSIZ
     56 #define	BUFSIZ		1024
     57 #endif
     58 #define MAXHOP		32		/* max number of tc= indirections */
     59 
     60 #define	tgetent		agetent
     61 #define	tnchktc		anchktc
     62 #define	tnamatch	anamatch
     63 #define	tgetnum		agetnum
     64 #define	tgetflag	agetflag
     65 #define	tgetstr		agetstr
     66 
     67 #if 0
     68 #define V_TERMCAP	"REMOTE"
     69 #define V_TERM		"HOST"
     70 #endif
     71 
     72 char	*RM;
     73 
     74 /*
     75  * termcap - routines for dealing with the terminal capability data base
     76  *
     77  * BUG:		Should use a "last" pointer in tbuf, so that searching
     78  *		for capabilities alphabetically would not be a n**2/2
     79  *		process when large numbers of capabilities are given.
     80  * Note:	If we add a last pointer now we will screw up the
     81  *		tc capability. We really should compile termcap.
     82  *
     83  * Essentially all the work here is scanning and decoding escapes
     84  * in string capabilities.  We don't use stdio because the editor
     85  * doesn't, and because living w/o it is not hard.
     86  */
     87 
     88 static	char *tbuf;
     89 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
     90 
     91 static	char *remotefile;
     92 
     93 extern char *conffile;
     94 
     95 int tgetent(char *, char *);
     96 int getent(char *, char *, char *);
     97 int tnchktc(void);
     98 int tnamatch(char *);
     99 static char *tskip(char *);
    100 int64_t tgetnum(char *);
    101 int tgetflag(char *);
    102 char *tgetstr(char *, char **);
    103 static char *tdecode(char *, char **);
    104 
    105 /*
    106  * Get an entry for terminal name in buffer bp,
    107  * from the termcap file.  Parse is very rudimentary;
    108  * we just notice escaped newlines.
    109  */
    110 int
    111 tgetent(char *bp, char *name)
    112 {
    113 	char *cp;
    114 
    115 	remotefile = cp = conffile ? conffile : __UNCONST(_PATH_RTADVDCONF);
    116 	return (getent(bp, name, cp));
    117 }
    118 
    119 int
    120 getent(char *bp, char *name, char *cp)
    121 {
    122 	int c;
    123 	int i = 0, cnt = 0;
    124 	char ibuf[BUFSIZ];
    125 	int tf;
    126 
    127 	tbuf = bp;
    128 	tf = 0;
    129 	/*
    130 	 * TERMCAP can have one of two things in it. It can be the
    131 	 * name of a file to use instead of /etc/termcap. In this
    132 	 * case it better start with a "/". Or it can be an entry to
    133 	 * use so we don't have to read the file. In this case it
    134 	 * has to already have the newlines crunched out.
    135 	 */
    136 	if (cp && *cp) {
    137 		tf = open(RM = cp, O_RDONLY);
    138 	}
    139 	if (tf < 0) {
    140 		syslog(LOG_INFO, "<%s> open: %m", __func__);
    141 		return (-2);
    142 	}
    143 	for (;;) {
    144 		cp = bp;
    145 		for (;;) {
    146 			if (i == cnt) {
    147 				cnt = read(tf, ibuf, BUFSIZ);
    148 				if (cnt <= 0) {
    149 					close(tf);
    150 					return (0);
    151 				}
    152 				i = 0;
    153 			}
    154 			c = ibuf[i++];
    155 			if (c == '\n') {
    156 				if (cp > bp && cp[-1] == '\\') {
    157 					cp--;
    158 					continue;
    159 				}
    160 				break;
    161 			}
    162 			if (cp >= bp + BUFSIZ) {
    163 				prog_write(2,"Remcap entry too long\n", 23);
    164 				break;
    165 			} else
    166 				*cp++ = c;
    167 		}
    168 		*cp = 0;
    169 
    170 		/*
    171 		 * The real work for the match.
    172 		 */
    173 		if (tnamatch(name)) {
    174 			close(tf);
    175 			return (tnchktc());
    176 		}
    177 	}
    178 }
    179 
    180 /*
    181  * tnchktc: check the last entry, see if it's tc=xxx. If so,
    182  * recursively find xxx and append that entry (minus the names)
    183  * to take the place of the tc=xxx entry. This allows termcap
    184  * entries to say "like an HP2621 but doesn't turn on the labels".
    185  * Note that this works because of the left to right scan.
    186  */
    187 int
    188 tnchktc(void)
    189 {
    190 	char *p, *q;
    191 	char tcname[16];	/* name of similar terminal */
    192 	char tcbuf[BUFSIZ];
    193 	char *holdtbuf = tbuf;
    194 	int l;
    195 
    196 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
    197 	while (*--p != ':')
    198 		if (p < tbuf) {
    199 			prog_write(2, "Bad remcap entry\n", 18);
    200 			return (0);
    201 		}
    202 	p++;
    203 	/* p now points to beginning of last field */
    204 	if (p[0] != 't' || p[1] != 'c')
    205 		return (1);
    206 	strlcpy(tcname, p + 3, sizeof tcname);
    207 	q = tcname;
    208 	while (*q && *q != ':')
    209 		q++;
    210 	*q = 0;
    211 	if (++hopcount > MAXHOP) {
    212 		prog_write(2, "Infinite tc= loop\n", 18);
    213 		return (0);
    214 	}
    215 	if (getent(tcbuf, tcname, remotefile) != 1) {
    216 		return (0);
    217 	}
    218 	for (q = tcbuf; *q++ != ':'; )
    219 		;
    220 	l = p - holdtbuf + strlen(q);
    221 	if (l > BUFSIZ) {
    222 		prog_write(2, "Remcap entry too long\n", 23);
    223 		q[BUFSIZ - (p-holdtbuf)] = 0;
    224 	}
    225 	strcpy(p, q);
    226 	tbuf = holdtbuf;
    227 	return (1);
    228 }
    229 
    230 /*
    231  * Tnamatch deals with name matching.  The first field of the termcap
    232  * entry is a sequence of names separated by |'s, so we compare
    233  * against each such name.  The normal : terminator after the last
    234  * name (before the first field) stops us.
    235  */
    236 int
    237 tnamatch(char *np)
    238 {
    239 	char *Np, *Bp;
    240 
    241 	Bp = tbuf;
    242 	if (*Bp == '#')
    243 		return (0);
    244 	for (;;) {
    245 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
    246 			continue;
    247 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
    248 			return (1);
    249 		while (*Bp && *Bp != ':' && *Bp != '|')
    250 			Bp++;
    251 		if (*Bp == 0 || *Bp == ':')
    252 			return (0);
    253 		Bp++;
    254 	}
    255 }
    256 
    257 /*
    258  * Skip to the next field.  Notice that this is very dumb, not
    259  * knowing about \: escapes or any such.  If necessary, :'s can be put
    260  * into the termcap file in octal.
    261  */
    262 static char *
    263 tskip(char *bp)
    264 {
    265 	int dquote;
    266 
    267 	dquote = 0;
    268 	while (*bp) {
    269 		switch (*bp) {
    270 		case ':':
    271 			if (!dquote)
    272 				goto breakbreak;
    273 			else
    274 				bp++;
    275 			break;
    276 		case '\\':
    277 			bp++;
    278 			if (isdigit((unsigned char)*bp)) {
    279 				while (isdigit((unsigned char)*bp++))
    280 					;
    281 			} else
    282 				bp++;
    283 		case '"':
    284 			dquote = (dquote ? 0 : 1);
    285 			bp++;
    286 			break;
    287 		default:
    288 			bp++;
    289 			break;
    290 		}
    291 	}
    292 breakbreak:
    293 	if (*bp == ':')
    294 		bp++;
    295 	return (bp);
    296 }
    297 
    298 /*
    299  * Return the (numeric) option id.
    300  * Numeric options look like
    301  *	li#80
    302  * i.e. the option string is separated from the numeric value by
    303  * a # character.  If the option is not found we return -1.
    304  * Note that we handle octal numbers beginning with 0.
    305  */
    306 int64_t
    307 tgetnum(char *id)
    308 {
    309 	int64_t i;
    310 	int base;
    311 	char *bp = tbuf;
    312 
    313 	for (;;) {
    314 		bp = tskip(bp);
    315 		if (*bp == 0)
    316 			return (-1);
    317 		if (strncmp(bp, id, strlen(id)) != 0)
    318 			continue;
    319 		bp += strlen(id);
    320 		if (*bp == '@')
    321 			return (-1);
    322 		if (*bp != '#')
    323 			continue;
    324 		bp++;
    325 		base = 10;
    326 		if (*bp == '0')
    327 			base = 8;
    328 		i = 0;
    329 		while (isdigit((unsigned char)*bp))
    330 			i *= base, i += *bp++ - '0';
    331 		return (i);
    332 	}
    333 }
    334 
    335 /*
    336  * Handle a flag option.
    337  * Flag options are given "naked", i.e. followed by a : or the end
    338  * of the buffer.  Return 1 if we find the option, or 0 if it is
    339  * not given.
    340  */
    341 int
    342 tgetflag(char *id)
    343 {
    344 	char *bp = tbuf;
    345 
    346 	for (;;) {
    347 		bp = tskip(bp);
    348 		if (!*bp)
    349 			return (0);
    350 		if (strncmp(bp, id, strlen(id)) == 0) {
    351 			bp += strlen(id);
    352 			if (!*bp || *bp == ':')
    353 				return (1);
    354 			else if (*bp == '@')
    355 				return (0);
    356 		}
    357 	}
    358 }
    359 
    360 /*
    361  * Get a string valued option.
    362  * These are given as
    363  *	cl=^Z
    364  * Much decoding is done on the strings, and the strings are
    365  * placed in area, which is a ref parameter which is updated.
    366  * No checking on area overflow.
    367  */
    368 char *
    369 tgetstr(char *id, char **area)
    370 {
    371 	char *bp = tbuf;
    372 
    373 	for (;;) {
    374 		bp = tskip(bp);
    375 		if (!*bp)
    376 			return (0);
    377 		if (strncmp(bp, id, strlen(id)) != 0)
    378 			continue;
    379 		bp += strlen(id);
    380 		if (*bp == '@')
    381 			return (0);
    382 		if (*bp != '=')
    383 			continue;
    384 		bp++;
    385 		return (tdecode(bp, area));
    386 	}
    387 }
    388 
    389 /*
    390  * Tdecode does the grung work to decode the
    391  * string capability escapes.
    392  */
    393 static char *
    394 tdecode(char *str, char **area)
    395 {
    396 	char *cp;
    397 	int c;
    398 	const char *dps = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"", *dp;
    399 	int i;
    400 	char term;
    401 
    402 	term = ':';
    403 	cp = *area;
    404 again:
    405 	if (*str == '"') {
    406 		term = '"';
    407 		str++;
    408 	}
    409 	while ((c = *str++) && c != term) {
    410 		switch (c) {
    411 
    412 		case '^':
    413 			c = *str++ & 037;
    414 			break;
    415 
    416 		case '\\':
    417 			dp = dps;
    418 			c = *str++;
    419 nextc:
    420 			if (*dp++ == c) {
    421 				c = *dp++;
    422 				break;
    423 			}
    424 			dp++;
    425 			if (*dp)
    426 				goto nextc;
    427 			if (isdigit((unsigned char)c)) {
    428 				c -= '0', i = 2;
    429 				do
    430 					c <<= 3, c |= *str++ - '0';
    431 				while (--i && isdigit((unsigned char)*str));
    432 			}
    433 			break;
    434 		}
    435 		*cp++ = c;
    436 	}
    437 	if (c == term && term != ':') {
    438 		term = ':';
    439 		goto again;
    440 	}
    441 	*cp++ = 0;
    442 	str = *area;
    443 	*area = cp;
    444 	return (str);
    445 }
    446